The invention relates to a brushless DC motor and a stator thereof, and in particular to a brushless DC motor and a stator thereof for stabilizing rotation and increasing rotation power of a rotor.
A disclosed stator structure for a brushless DC motor includes a lower magnetic pole piece having leg portions radially extending from the magnetic pole of the lower magnetic pole piece. Each of the leg portions supports a ring sheet. The ring sheets are used to interact with a permanent magnet of a rotor to generate attraction therebetween to stabilize the rotation of the rotor. Although slanting, vibration, undesirable friction and noise from the shaft of the rotor can be eliminated by this stator structure, axial attraction may hinder the rotation of the rotor. Further, because only increasing the number of the stacked magnetic pole pieces can improve the performance efficiency of the motor, the usable space in the motor is limited, especially in a miniature motor.
Also, there is a conventional brushless DC motor having an outer rotor and a plurality of upper and lower magnetic pole pieces correspondingly bent and complementarily arranged to increase the effective magnetic area. However, vibration in the axial direction of the rotor can not avoid.
Thus, to overcome the disclosed problems, the invention provides a miniature brushless DC motor to rapidly enhance rotation speed and effectively stabilize the rotation thereof.